


Dominant Species

by shini02



Category: Big Hero 6 (2014), Disney - All Media Types, The Little Mermaid (1989), X-Men - All Media Types
Genre: AU, Crossover, Gen
Language: English
Status: Completed
Published: 2015-08-16
Updated: 2015-08-22
Packaged: 2018-04-15 02:44:14
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 4,800
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4590063
Author URL: https://archiveofourown.org/users/shini02/pseuds/shini02
Summary: <blockquote class="userstuff">
              <p>A collection of oneshots, drabbles, ficlets and vignettes. Mutant!AU. You've been given genetically altered abilities which separate you from the rest of the human race. Deal with it. • Just Add Water: The day her family plans to go to the beach, Ariel wakes with strange pains in her legs.</p>
            </blockquote>





	1. From the Ashes

**Summary for the Chapter:**

> Tadashi is not gone. In fact, Tadashi is right here, and he remembers fire, he remembers burning.

"Someone has to help."

He would like to be able to say that he doesn't think twice about running into the burning building, but he does. He thinks about the fire and how quickly it's spreading, and he thinks about Hiro and how took hold of his wrist and held on so tight. He tells himself this is the right thing to do, because someone has to at least try and save Callaghan, but as good and just as all of this is, he really wishes it wasn't him. Hiro needs him, and if anything happens here – if something goes wrong –

No. No, he can't think about that, not right now. He has to focus on the task at hand and push his way through the fire. He has to find Callaghan, and he tells himself he will. He will find him and they will get out together, and he will have never had to worry about Hiro. His brother's finally on the right track, doing something good and useful with that big, wonderful brain of his, and he can't leave him alone now.

But it's getting harder to breathe the farther in he goes. The heat is intense, like nothing he's ever felt before, and the air is so thick that it's a struggle to suck in, and it burns coming back out. Whatever hope he had of both he and Callaghan making it out alive is beginning to dwindle, but he resolves that at least he will have tried, and that's what will matter in the end.

He calls out for Callaghan, forces his voice through the hot and heavy atmosphere and hopes it carries. It's hard to hear anything beyond the roar of flames and the hiss of toxic materials, but he strains his ears, hoping to catch even a whimper from the other man.

Every sensible nerve in his body is begging him to turn back while he still can, but then he sees something through the flames that gives him the tiniest flicker of hope. The shape is distorted through the flames, but it's humanoid and dark, and Tadashi doesn't think twice as he pushes onward and toward the figure. It has to be Callaghan, and so he calls for him again, and he sees that it is Callaghan, and Hiro's microbots are surrounding him. He wants to ask why, and how, but those questions can wait because they have to get out of this building before –

Something overhead creaks in a way that makes Tadashi's stomach twist and knot. He reaches out toward Callaghan, and Callaghan is using the microbots to reach back for him, and they're so close to making contact. Just a little farther –

Support structures from above suddenly give way, and Callaghan doesn't have time to protect both himself and Tadashi from them. When the microbots split apart to let him see, Tadashi is pinned beneath what used to be a part of the ceiling and fire. Even if he wanted to, he doubts there is anything he could do to save him now.

Callaghan leaves and Tadashi is barely conscious, but he's coherent enough to realize he had this whole situation wrong. Trying didn't matter, because Callaghan wasn't worth risking his life for. Callaghan wasn't worth dying for. Even if he had the strength to try and save himself now, the fire is fed and fueled by too many toxins and it puts up a stronger fight.

There's an explosion, and he burns, and his screams are swallowed by the blaze. By the time the fire has been brought under control and put out, there is no body left to salvage.

* * *

Hours pass and the embers have long since cooled. All that remains of San Fransokyo Tech is are ruins and ashes, but the plans to rebuild are already underway. Callaghan is presumed dead, as no body or even traces of one could be found. Tadashi is also counted among the casualties; shreds of scorched clothing was recovered, but nothing more. They are mistaken, though.

Tadashi isn't gone.

In fact, Tadashi is right here.

There is a pile of ash that is not like the rest, and it begins to smoulder again. It stirs and shifts until it starts to take on a shape of its own. First hands come, followed by arms, shoulders, and a torso. Hips come next, then legs and feet, and the body struggles to stand. It gropes at the air blindly until the head is finished forming, and when it has a mouth, it draws in a gasp so strong that the embers in its core glow for just a moment. When the eyes have formed, they blink away fog and smoke before they focus properly.

He sees the charred ruins of the school, and realizes he's standing right in the middle of it all. The next thing he notices as his panic starts to build are his hands, and then the rest of his body. He's made entirely out of blackened ash and embers, and then he remembers. He remembers the exhibition, the fire, Callaghan, the explosion, burning –

There's a scream trapped in his throat that he just can't seem to will out, no matter how hard he tries. He's fairly certain he died, he remembers very clearly what it was like to cease to exist. But then, what is this now? What is he, and why is this happening?

In his distress, he barely notices the ash fall away, revealing his skin underneath. Now he stands there within these ruins, naked and in shock, not sure what to make of any of this, especially himself.

Through all the thoughts rattling about inside his brain, one suddenly sounds out among the rest. It stands out because it's not his own. There is a woman's voice in his mind whispering,  _you're alright_  and  _calm down_  and  _we are here to help_. Despite the voice trying to be comforting, naturally it only makes him panic a little more.

"I know you're scared," the voice says again, except this time it's not in his head and it's coming from just a few feet away. He twists himself around to see a woman and a man coming toward him. She is gorgeous, and scantily dressed from head to toe in white. The man looks intimidating in his dark uniform and with his eyes hidden behind a red visor.

Tadashi wants to ask  _who are you_ and  _what do you want_  but the questions are lodged in his throat, much like the scream had been. But he doesn't need to ask, anyway, because the woman already knows, and she's answering him.

"My name is Emma Frost, and this is Scott Summers. We are X-Men, and – as I said before – we are here to help you, Tadashi." She grins at him, cocky and so sure of herself, but there's something else, something almost reassuring in the curl of her lips. If he hadn't just come back from the dead, from being nothing but a pile of smoldering ash, he would have seriously questioned this woman's ability to read his mind. Though, it went without mentioning that the microbot technology had heavily relied on telepathic communication between host and machine, and so it wasn't entirely impossible –

"I'm very glad to see you're beginning to rationalize your situation,, Mr. Hamada, but we don't have time for that right now," Emma says, rubbing at one temple.

"I'm sorry," Tadashi finally speaks, clearing his throat and glancing downward. This is when he remembers, or perhaps realizes, that he's been naked this whole time and he quickly uses his hands to cover himself.

"I know this is a lot to take in," Scott says, and his voice is and tone are surprisingly gentle. "But what happened to you – the accident – it triggered your powers' manifestation."

"Most mutants are so lucky to have their powers come in, per se, during a traumatic experience," Emma explains while unhitching the cape she wears from her shoulders. She comes closer to him, stepping through rubble and ash to wrap the white cloth around his shoulders.

As he takes a tight hold of the cape and uses it to cover himself better, and watches Emma step back to stand at Scott's side, Tadashi's mind is racing again. He's heard about mutants before and all of their doing, good and bad alike, but this can't be happening. He can't be –

"But you are," Emma says, and she says it in a way that tells him there will be no arguing with her. Besides, even if he wanted to argue, to continue to deny it, the facts are very much against him at the moment. So he takes a moment, takes a breath, and takes it in.

"Okay," he says, nodding. "So, you said you're here to help me. How?" he asks and his brow furrows again as he looks between Scott and Emma. As he looks at them, he gets this feeling this is not the first time they have done this, and he is not the first they have come to.

"We can teach you how to control it," Scott says, as though it's as simple as that. And maybe it is.

Considering he has no idea how his own body works anymore, and that's a terrifying realization to come to, learning control sounds not only like a good idea but a necessity. Still, he has questions, namely:

"Teach me control, how?"

"At our school," Emma tells him, and that grin is back on her lips, which Tadashi notes now are painted a silvery-blue.

"Mutant school?" he blurts out, and there's a small grin on his lips.

"Exactly," Scott replies, and his lips curve upward in the slightest, too.

Tadashi nods again, but his brow slowly knits together once more. "But what about my brother? And my aunt?" he asks. "They – they don't know I'm… alive." And it's just a little harder than expected to choke that sentence out, because that means coming to terms with the fact he actually may have been dead.

"It's your choice if you want to reveal yourself to your family or not," Emma says bluntly, crossing her arms over her chest. "But given the highly destructive properties of your powers, I can't recommend staying with them until you've mastered them."

Tadashi sees her point almost instantly. He can't let his family continue to think he's dead, but he won't put them in harm's way, either.

"And this school," he starts, slow and cautious, because now he's analyzing everything, weighing every option, "it actually helps?"

Scott and Emma share a glance that only lasts a moment, but Tadashi gets this feeling that an entire and very private conversation takes place within it. When they look toward Tadashi again, Scott has a small smile on his lips again. Somehow, this one is different than the last, but Tadashi can't quite figure out how, or why.

"Yes," he says. "It helps."

Tadashi holds Emma's cloak just a little tighter to his body. As far as he can tell, the pros outweigh the cons, and he trusts these strangers. "Okay," he says, but his gaze narrows now, just a little. "I'll go with you, but only until I get… this under control."

"Of course," Emma says, then turns on her heel and begins to walk away. "Come along then, dear."

Tadashi watches her for a moment, and then looks back at Scott. The older man gives a nod in Emma's direction, then follows after her. Tadashi hesitates for a few seconds more before stepping out of the rubble and following the two. They walk in silence for a short distance, and Tadashi almost wonders where they're going when they suddenly come to a stop. They've wound up in the middle of an empty park, and just when more questions start to come to mind, like  _why are we here_  and  _what are we doing_ , something happens. A large black jet seemingly appears out of nowhere, but after the surprise at least settles in him, he understands it had always been there, just camouflaged.

Emma and Scott lead him up the small flight of stairs and into the jet. He marvels at the interior just for a moment before he realizes they aren't alone in this magnificent machine. There is a man in the pilot's seat, twisted around and with one arm draped over the back of it, grinning at him. There's another man sitting at the front of one of rows of seats, and Tadashi can't help but stare at him. For the most part, everyone in the jet looks perfectly normal – he would have never guessed Emma could read minds just by looking at her, and he still doesn't know what Scott's powers are. The man at the controls looks like an average, everyday person, too. The other man, though, while he does look normal, he has a pair of large, white-feathered wings growing out of his back.

"This is Warren," Scott says, motioning to the winged man, since he had most of his attention. Warren gives him a small smile and a nod, and then Scott directs his attention toward the other, "and that's Bobby."

"Yo," Bobby grins and gives Tadashi a little wave. "Welcome aboard, kid."

"Thanks," Tadashi replies slowly, letting Emma now lead him to the row opposite Warren.

Scott takes a seat in the co-pilot's chair. "Let's get him home."

"You're the boss," Bobby says as he shifts around to face the controls. Tadashi doesn't need to see his face to know he's grinning.

As the jet takes off, Tadashi's mind begins to wander again. There are so many questions flitting through his mind, but he doesn't have the energy to ask them all. He so desperately wants to understand all of this, but he knows from experience that some things just take time and patience and hard work before they start making any kind of sense.


	2. Just Add Water

**Summary for the Chapter:**

> The day her family plans to go to the beach, Ariel wakes with strange pains in her legs.

The day her family plans to go to the beach, Ariel wakes with terrible pains in her legs. The cramps are sharp, and they shoot straight from her hips all the way down to the soles of her feet. With every step she takes, it feels as though she's walking on glass, but she doesn't make too much of a fuss. She doesn't want her sisters or father worrying over her, and she definitely doesn't want to ruin the day with any complaints. Besides, the cold ocean water will probably help to soothe the aches.

By the time she and her sisters pile into the family van, she's come to a point where she's convinced herself that the pain isn't so bad and that it's nothing to worry herself over. It's probably just some sort of growing pain, or something of a similar sort. She is only sixteen, after all, and her body is far from finished changing. Her sisters are a good distraction, too, and they help keep her mind off of it. When they arrive at the beach, she's able to almost completely ignore the horrible tingles that race up and down her legs.

Their family is large and so they find a secluded spot further down the beach, away from the rest of the beach-goers. They set up there; their father with a beach chair, and each of her sisters with a towel to lay out on the hot sand. Her father is content to lounge, and most of her sisters prefer to tan, but she's excited to get into the water.

"Ariel, I don't want to go!" Arista whines while her younger sister holds on to her wrist tightly, tugging her toward the ocean.

"Oh, come on! Just one swim!" Ariel coaxes. "Then I'll leave you alone for the rest of the day."

"But - my hair," Arista pouts and uses her free hand to rake her fingers through her blonde locks.

"Excuses!" Ariel grins and rolls her eyes. "You don't have to get your hair wet."

"Just get it over with," Attina calls from her place just a little further up the beach where she rests with their other sisters. "You know she's not going to give up."

Arista whines again, but gives in and lets Ariel continue to tug her closer and closer to the ocean. Just before they reach it, however, Arista gives Ariel a sharp tug of her own, and they twist and stumble until Arista is the one pulling Ariel. It takes only a few moments before the two of them are dancing clumsily at the water's edge, pushing and pulling, each trying to get the other into the water first.

The water laps, just once, at Ariel's feet, and a new, sharper pain shoots up her legs. She gasps and winces, and that's the moment decides to use to her advantage. She shoves at Ariel hard, and the redhead stumbles and trips, falling back into the cold waves lapping at the shore.

Arista laughs, and Ariel can hear their sisters laughing from the shore, too. She would probably join them, if not for the excruciating pain suddenly coursing through her lower-half.

It doesn't take long for Arista to realize the fun and games are over, and that something's wrong. "Ariel?" she asks, brow furrowing as she looks at her sister, and she can see the panic and pain as clear as day on her pretty face. "What's wrong?"

Ariel struggles to form words, but she manages to choke out, "it hurts."

"What hurts?" Arista asks, and then she sees Ariel's hand at her thigh, her nails digging into her flesh. "Your legs?" She frowns and gets down on her knees in the shallows to be closer to Ariel. "Let me see."

Ariel's breathing is fast and clumsy as she leans back on her palms in the water, lifting her knees, whimpering as the pains surge through her. When her knees break the surface of the water, her eyes widen in shock and confusion. There are strange green patches spreading across her pale skin. Her hand moves quickly, and she touches one of the patches, and she finds it's slick and scaly under her fingers.

Arista has leaned back and she's gaping at Ariel in a little bit of shock, but mostly fear. "What's going on?"

Ariel shakes her head and tries to get her erratic breathing under control. "I - I don't know!"

Arista panics, and does the only thing she can think of: she calls for their father. It takes only seconds before Triton and all of their sisters are rushing over to the two of them.

"What's wrong?" Triton asks, pushing Arista aside gently and getting down on his knees beside Ariel.

"We don't know, but she's hurting, Daddy," Arista explains and frowns, standing to give their father room.

The scales are spreading faster, and it's only when Ariel tries to maneuver one leg at a time that she realizes her legs can't move on their own. At first she thinks it's the pain restricting her movement, muscles stiff and locked, but then she notices her legs are fusing together. Beneath her flesh, she can feel her bones and muscles and everything in between changing, too.

And the scales keep spreading, up over her hips and down to her toes.

"Daddy?" she whimpers, but when she looks up and away from the mangled mess that used to be her legs, she sees her father staring at her in nothing short of horror and disgust.

Triton stands and starts to back away, offering his youngest daughter no comfort as her legs morph into a fish's tail before his very eyes.

 

* * *

 

 

It's later into the evening when the Blackbird lands in a secluded part of the beach. The heat has left the sand, and the wind that sweeps in off the waves is cold, and so most visitors have left. The one Logan came here for, however, is still here, and that's all that matters to him. He steps out of the jet, and glances over his shoulder once at the boy he brought along, just to make sure he's following. Sammy is young and a little headstrong, but he's a good kid, and taking into account what the White Queen had told them about this new mutant, Logan felt this was a good chance for the kid to get some practice in the field.

"I don't know why I had to come," Sammy says as he steps down onto the cooled sand. His hands are in his pockets, and his head is bowed as he walks behind the Wolverine.

"Birds of a feather, kid," Logan says, walking on, following the scent of the new mutant.

"I'm a fish, not a bird," Sammy mumbles, brow furrowing. He thinks this is a bad idea, doesn't understand why Logan would want him on this recruiting mission. This new mutant's going to take one look at him and scream, or laugh, or cry. Maybe all of the above.

"Same difference," Logan says, and Sammy doesn't see the small, crooked smirk on his chapped lips.

"I doubt it," the boy says with a small sigh and a heave of his shoulders.

They walk the rest of the way in silence, and when Logan finally spots her, he slows the pace down. She's propped up against a sand dune, tail brought up and bent like knees, hugged to her chest. Her face is pushed into her arms, and she shudders every time the water creeps up the short and laps at her fin. There's a saltiness in the air that doesn't belong to the sea, and Logan sighs softly before he approaches her.

Sammy follows him, slowly, just a little surprised to see the girl they've come to save. Now he understands why Logan brought him along - sort of, anyway. He doubts looking at his ugly face is going to help her at all, but if she had been under water, he gets that it would have been easier for him to get to her.

All that aside, though, he can't help but marvel at her just a little. He knows she's a mutant, but he's still a kid, and for just a moment he lets himself think of her as exactly what she looks like: a mermaid.

Hearing the sand crunch beneath Logan's heavy boots, Ariel looks up, surprised and afraid. She moves clumsily, tries to drag herself away, but stops when she sees Logan kneel and shake his head.

"Relax, darlin', we ain't here to hurtcha," he tells her, and his gruff voice is soft.

Ariel swallows hard and sucks in a few deep breaths. "Who are you?" she asks, looking this strange man over intently. Logan can see it in her eyes, the desperate need to be helped, to be saved.

"The name's Logan," he says, and nods over his shoulder in Sammy's direction. "And that there's Sammy. We're here to help you."

Ariel's gaze follows Logan's direction to Sammy, and her eyes widen just a little. She can't help but stare, because he looks so much like a fish, and she has to wonder if this man brought him along on purpose.

"Help...?" she asks, bringing her eyes back to Logan. She swallows hard and uses the back of her hand to wipe at one of her reddened, wet eyes. "How?"

Logan opens his mouth to explain, but Sammy pushes passed him and furrows his brow as he stares down at the pretty redhead. "There's this school, and they help kids like us get - " he pauses for a moment because he almost says 'better' but it doesn't really get better, not for kids like him. "...get used to this," he says instead, and motions to himself, and then to her tail.

Ariel swallows hard again and looks between Sammy and Logan. She believes them, but this is a lot to take in, and she doesn't know how she's supposed to feel.

"...my father and sisters," she says slowly, and her gaze falls down to her new green scales. "They left me. Daddy - he said he won't have a mutant for a daughter." And the tears come again.

"Well, joke's on him, 'cause he always had one, he just didn't know it," Logan says, and something about his bluntless helps, but not a whole lot.

"Screw them, then!" Sammy says quickly, a little louder than he means to. "The people at Xavier's will love you no matter what. So... don't cry, okay?"

Ariel smiles a little, looking up at Sammy's face. He's so young, but he's so determined to help.

"Besides, you don't got it that bad," he continues and motions to himself. "You could look like this. But you got that awesome tail! You're a freakin' mermaid! How cool is that?!"

Logan grins, keeping quiet for now. He had known bringing Sammy would be a good idea.

Ariel's smile broadens just a little as she looks from Sammy and down to her tail. She stretches it carefully, and the pains that were so terrible just hours ago have disappeared all together. She takes this moment to really look at it, and some part of her appreciates its beauty.

"So, what do you say, darlin'?" Logan asks. "you wanna give this a shot?"

She hesitates for a few long seconds, weighs her options, though they aren't really worth comparing. She can either stay here and figure this new life out on her own, or she can accept the opportunity being offered to her and learn how to make the best of it. The choice seems fairly obvious.

She swallows hard and nods. "I'll go with you," she says, and she sees both Sammy and Logan smile their own unique smiles.

"Lemme give ya a hand," Logan says and carefully lifts Ariel into his arms. She wraps her arms around his neck, and ducks her head, just a little shy.

"You don't have to - "

"We're not gonna make you crawl to the jet," Sammy says with a smirk, walking along side Logan when the older man starts back toward the Blackbird.

Ariel smiles weakly, but perks up just a moment later. "Jet?"

Sammy grins up at the redhead, shoving his hands back into his pockets. "The X-Men don't mess around. We have a jet, and we live in a mansion."

Ariel's eyes widen just a little, and she mouths a quiet, "oh." She wonders about the X-Men, but she'll save that question, along with the dozens of others slowly surfacing in her mind, for later. For now, she just tries to calm herself down; this whole experience has taken a toll on her, but she appreciates whatever help Sammy and Logan are offering.

They enter the Blackbird, and Logan gives her a blanket to cover herself with. The only thing she's wearing now is the purple top of the bikini she had been wearing. The bottoms had been torn apart when her legs changed into a tail, but she doesn't even think twice about that. The bathing suit is not important. She draws the blanket close to herself, and thinks about her family. She thinks about her father, and how he urged her sisters away from her as though she had been diseased. She thinks about how he didn't think twice before leaving her alone on the beach to fend for herself.

She wonders if, after his anger and fear left him, if he'd go back to the beach to find her. She wonders what he'd do when he found her gone, and if he'd worry or even care.

She likes to think so.

Her father isn't a bad man, just very set in his ways. And, unfortunately, those ways are very anti-mutant. But maybe now that he has a mutant for a daughter, he'll change the way he thinks once he's had the time to process it all with a clear mind.

"...hey, try not to think about it too much, okay?" Sammy says from across the aisle, and Ariel jerks a little at the sound of his voice. She looks at him, and he notices just how blue her eyes are. "I know it sucks," he says with a small shrug, "but this school... it'll help. It'll be okay."

She swallows hard and shapes her mouth into a small O, exhaling. She nods and gives him a small smile again. "Okay."

"What's your name, by the way?" Sammy asks. If Logan knew it, he never used it, and Sammy hadn't thought to ask until now.

"Ariel," she says, and Sammy smiles.

"That's a pretty name."

She smiles back at him. "Thank you."

"I'm glad you came with us, Ariel," he says, and Ariel's smile softens.

"I am, too, Sammy."


End file.
